Bug 533701: [Sequence Diagram] Stereotype or Shape Compartments should

not
be displayed in CombinedFragments
https://bugs.eclipse.org/bugs/show_bug.cgi?id=533701

Add 2 services, to support filtering generic Papyrus IViewProviders and
IEditPolicyProviders. Also add a simple contribution for the Sequence
Diagram, to disable Symbols compartments.

Change-Id: I0d6e1af0ad4395daf3170409b5735df36dd02d46
Signed-off-by: Camille Letavernier <cletavernier@eclipsesource.com>

10 files changed, 464 insertions, 2 deletions

diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/internal/service/EditPolicyProviderServiceImpl.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/internal/service/EditPolicyProviderServiceImpl.java
new file mode 100644
index 00000000000..ad13bf561cc
--- /dev/null
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/internal/service/EditPolicyProviderServiceImpl.java
@@ -0,0 +1,41 @@
+/*****************************************************************************
+ * Copyright (c) 2018 EclipseSource and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   EclipseSource - Initial API and implementation (Bug 533701)
+ *
+ *****************************************************************************/
+package org.eclipse.papyrus.infra.gmfdiag.common.internal.service;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.eclipse.gef.EditPart;
+import org.eclipse.gmf.runtime.diagram.ui.services.editpolicy.IEditPolicyProvider;
+import org.eclipse.papyrus.infra.gmfdiag.common.service.EditPolicyProviderService;
+import org.eclipse.papyrus.infra.gmfdiag.common.service.EditPolicyProviderTester;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
+
+import com.google.common.base.Predicates;
+
+@Component
+public class EditPolicyProviderServiceImpl implements EditPolicyProviderService {
+
+	private Set<EditPolicyProviderTester> testers = new HashSet<>();
+
+	@Override
+	public boolean isEnabled(IEditPolicyProvider provider, EditPart editPart) {
+		return testers.stream().map(tester -> tester.isEnabled(provider, editPart)).noneMatch(Predicates.equalTo(Boolean.FALSE));
+	}
+
+	@Reference
+	public void registerTester(EditPolicyProviderTester tester) {
+		testers.add(tester);
+	}
+}
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/internal/service/ViewProviderServiceImpl.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/internal/service/ViewProviderServiceImpl.java
new file mode 100644
index 00000000000..64b6ed738ae
--- /dev/null
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/internal/service/ViewProviderServiceImpl.java
@@ -0,0 +1,40 @@
+/*****************************************************************************
+ * Copyright (c) 2018 EclipseSource and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   EclipseSource - Initial API and implementation (Bug 533701)
+ *
+ *****************************************************************************/
+package org.eclipse.papyrus.infra.gmfdiag.common.internal.service;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.eclipse.gmf.runtime.diagram.core.providers.IViewProvider;
+import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.papyrus.infra.gmfdiag.common.service.ViewProviderService;
+import org.eclipse.papyrus.infra.gmfdiag.common.service.ViewProviderTester;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
+
+@Component
+public class ViewProviderServiceImpl implements ViewProviderService {
+
+	private Set<ViewProviderTester> testers = new HashSet<>();
+
+	@Override
+	public boolean isEnabled(IViewProvider provider, View view) {
+		return testers.stream().map(tester -> tester.isEnabled(provider, view)).reduce(true, Boolean::logicalAnd);
+	}
+
+	@Reference
+	public void registerTester(ViewProviderTester tester) {
+		testers.add(tester);
+	}
+
+}
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/CustomAbstractViewProvider.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/CustomAbstractViewProvider.java
index eb02c910275..055aa16e510 100644
--- a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/CustomAbstractViewProvider.java
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/CustomAbstractViewProvider.java
@@ -24,6 +24,7 @@ import org.eclipse.gmf.runtime.notation.Diagram;
 import org.eclipse.gmf.runtime.notation.Edge;
 import org.eclipse.gmf.runtime.notation.Node;
 import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.papyrus.infra.gmfdiag.common.service.ProviderServiceUtil;
 import org.eclipse.papyrus.infra.viewpoints.policy.ViewPrototype;
 
 /**
@@ -61,6 +62,9 @@ public abstract class CustomAbstractViewProvider extends AbstractViewProvider {
 	 */
 	@Override
 	protected boolean provides(CreateViewForKindOperation op) {
+		if (!ProviderServiceUtil.isEnabled(this, op.getContainerView())) {
+			return false;
+		}
 		if (!isRelevantDiagram(op.getContainerView().getDiagram())) {
 			return false;
 		}
@@ -81,6 +85,9 @@ public abstract class CustomAbstractViewProvider extends AbstractViewProvider {
 	 */
 	@Override
 	protected boolean provides(CreateEdgeViewOperation operation) {
+		if (!ProviderServiceUtil.isEnabled(this, operation.getContainerView())) {
+			return false;
+		}
 		if (!isRelevantDiagram(operation.getContainerView().getDiagram())) {
 			return false;
 		}
@@ -93,6 +100,9 @@ public abstract class CustomAbstractViewProvider extends AbstractViewProvider {
 	 */
 	@Override
 	protected boolean provides(CreateNodeViewOperation operation) {
+		if (!ProviderServiceUtil.isEnabled(this, operation.getContainerView())) {
+			return false;
+		}
 		if (!isRelevantDiagram(operation.getContainerView().getDiagram())) {
 			return false;
 		}
@@ -138,7 +148,7 @@ public abstract class CustomAbstractViewProvider extends AbstractViewProvider {
 
 	/**
 	 * This method is used to know id the diagram is conform to type, it may be a prototype view, or a generatedDiagram
-	 * 
+	 *
 	 * @param diagram
 	 * @return
 	 */
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/CustomEditPolicyProvider.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/CustomEditPolicyProvider.java
index d3d717f2201..b3923d22860 100644
--- a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/CustomEditPolicyProvider.java
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/CustomEditPolicyProvider.java
@@ -23,6 +23,7 @@ import org.eclipse.papyrus.infra.core.services.ServiceException;
 import org.eclipse.papyrus.infra.core.services.ServicesRegistry;
 import org.eclipse.papyrus.infra.emf.utils.EMFHelper;
 import org.eclipse.papyrus.infra.gmfdiag.common.editpolicies.HighlightEditPolicy;
+import org.eclipse.papyrus.infra.gmfdiag.common.service.ProviderServiceUtil;
 import org.eclipse.papyrus.infra.gmfdiag.common.utils.ServiceUtilsForEditPart;
 
 /**
@@ -70,8 +71,11 @@ public class CustomEditPolicyProvider implements IEditPolicyProvider {
 	 * {@inheritDoc}
 	 */
 	@Override
-	public boolean provides(IOperation operation) {	
+	public boolean provides(IOperation operation) {
 		CreateEditPoliciesOperation epOperation = (CreateEditPoliciesOperation) operation;
+		if (!ProviderServiceUtil.isEnabled(this, epOperation.getEditPart())) {
+			return false;
+		}
 		try {
 			EditPart editPart = epOperation.getEditPart();
 			if (!(editPart instanceof GraphicalEditPart)) {
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/ExternalReferenceEditPolicyProvider.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/ExternalReferenceEditPolicyProvider.java
index 39dd468c4b0..df832001fad 100644
--- a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/ExternalReferenceEditPolicyProvider.java
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/providers/ExternalReferenceEditPolicyProvider.java
@@ -19,6 +19,7 @@ import org.eclipse.gmf.runtime.diagram.ui.services.editpolicy.IEditPolicyProvide
 import org.eclipse.gmf.runtime.notation.Node;
 import org.eclipse.papyrus.infra.core.services.ServiceException;
 import org.eclipse.papyrus.infra.gmfdiag.common.editpolicies.ExternalReferenceEditPolicy;
+import org.eclipse.papyrus.infra.gmfdiag.common.service.ProviderServiceUtil;
 import org.eclipse.papyrus.infra.gmfdiag.common.utils.ServiceUtilsForEditPart;
 
 /**
@@ -35,6 +36,9 @@ public class ExternalReferenceEditPolicyProvider extends AbstractProvider implem
 	public boolean provides(IOperation operation) {
 		if (operation instanceof CreateEditPoliciesOperation) {
 			CreateEditPoliciesOperation createOperation = (CreateEditPoliciesOperation) operation;
+			if (!ProviderServiceUtil.isEnabled(this, createOperation.getEditPart())) {
+				return false;
+			}
 			try {
 				if (ServiceUtilsForEditPart.getInstance().getServiceRegistry(createOperation.getEditPart()) != null) {
 					return createOperation.getEditPart().getModel() instanceof Node;
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/EditPolicyProviderService.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/EditPolicyProviderService.java
new file mode 100644
index 00000000000..ed026605c72
--- /dev/null
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/EditPolicyProviderService.java
@@ -0,0 +1,77 @@
+/*****************************************************************************
+ * Copyright (c) 2018 EclipseSource and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   EclipseSource - Initial API and implementation (Bug 533701)
+ *
+ *****************************************************************************/
+
+package org.eclipse.papyrus.infra.gmfdiag.common.service;
+
+import org.eclipse.gef.EditPart;
+import org.eclipse.gmf.runtime.diagram.ui.services.editpolicy.IEditPolicyProvider;
+import org.eclipse.papyrus.infra.core.services.IServiceFactory;
+import org.eclipse.papyrus.infra.core.services.ServiceException;
+import org.eclipse.papyrus.infra.core.services.ServicesRegistry;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.FrameworkUtil;
+import org.osgi.framework.ServiceReference;
+
+/**
+ * <p>
+ * A service used to increase the control diagrams have over the {@link IEditPolicyProvider}
+ * that should be enabled in that diagram. All generic Papyrus {@link IEditPolicyProvider} are expected to use this
+ * service before deciding if they should indeed be enabled.
+ * </p>
+ * <p>
+ * Note that this service is here to provide an additional pre-check to determine if a
+ * provider is allowed to work in a specific diagram. However, this service knows nothing
+ * about the internal requirements/dependencies of a specific provider, and should not
+ * <strong>replace</strong> the {@link IEditPolicyProvider#provides(org.eclipse.gmf.runtime.common.core.service.IOperation)}
+ * method (i.e. the actual provider is still expected to run its own checks, in addition
+ * to calling this service).
+ * </p>
+ *
+ * @since 3.100
+ */
+public interface EditPolicyProviderService {
+
+	/**
+	 * Tests whether the given provider is allowed in the context of that edit part
+	 *
+	 * @param provider
+	 * @param editPart
+	 * @return
+	 */
+	boolean isEnabled(IEditPolicyProvider provider, EditPart editPart);
+
+	public static class Factory implements IServiceFactory {
+
+		@Override
+		public void init(ServicesRegistry servicesRegistry) throws ServiceException {
+			// Nothing
+		}
+
+		@Override
+		public void startService() throws ServiceException {
+			// Nothing
+		}
+
+		@Override
+		public void disposeService() throws ServiceException {
+			// Nothing
+		}
+
+		@Override
+		public EditPolicyProviderService createServiceInstance() throws ServiceException {
+			BundleContext bundleContext = FrameworkUtil.getBundle(Factory.class).getBundleContext();
+			ServiceReference<EditPolicyProviderService> serviceReference = bundleContext.getServiceReference(EditPolicyProviderService.class);
+			return bundleContext.getService(serviceReference);
+		}
+	}
+}
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/EditPolicyProviderTester.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/EditPolicyProviderTester.java
new file mode 100644
index 00000000000..7bfd7ad94dc
--- /dev/null
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/EditPolicyProviderTester.java
@@ -0,0 +1,39 @@
+/*****************************************************************************
+ * Copyright (c) 2018 EclipseSource and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   EclipseSource - Initial API and implementation (Bug 533701)
+ *
+ *****************************************************************************/
+
+package org.eclipse.papyrus.infra.gmfdiag.common.service;
+
+import org.eclipse.gef.EditPart;
+import org.eclipse.gmf.runtime.diagram.ui.services.editpolicy.IEditPolicyProvider;
+
+/**
+ * <p>
+ * A contribution to the {@link EditPolicyProviderService}
+ * </p>
+ *
+ * @since 3.100
+ */
+public interface EditPolicyProviderTester {
+
+	/**
+	 * Tests whether the given provider is allowed in the context of that edit part
+	 *
+	 * @param provider
+	 * @param editPart
+	 * @return
+	 * 		<code>false</code> if this tester explicitly rejects this provider in the context of that edit part;
+	 *         <code>true</code> otherwise.
+	 */
+	boolean isEnabled(IEditPolicyProvider provider, EditPart editPart);
+}
+
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ProviderServiceUtil.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ProviderServiceUtil.java
new file mode 100644
index 00000000000..adbbcde0f5e
--- /dev/null
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ProviderServiceUtil.java
@@ -0,0 +1,130 @@
+/*****************************************************************************
+ * Copyright (c) 2018 EclipseSource and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   EclipseSource - Initial API and implementation (Bug 533701)
+ *
+ *****************************************************************************/
+package org.eclipse.papyrus.infra.gmfdiag.common.service;
+
+import org.eclipse.gef.EditPart;
+import org.eclipse.gmf.runtime.diagram.core.providers.IViewProvider;
+import org.eclipse.gmf.runtime.diagram.ui.services.editpolicy.IEditPolicyProvider;
+import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.papyrus.infra.core.services.ServicesRegistry;
+import org.eclipse.papyrus.infra.emf.utils.ServiceUtilsForEObject;
+import org.eclipse.papyrus.infra.gmfdiag.common.utils.ServiceUtilsForEditPart;
+
+/**
+ * <p>
+ * Utility methods to use the {@link ViewProviderService} and {@link EditPolicyProviderService}
+ * </p>
+ *
+ * @since 3.100
+ */
+public class ProviderServiceUtil {
+
+	/**
+	 * <p>
+	 * Tests if the given edit part is a Papyrus Edit Part, by testing if a Papyrus {@link ServicesRegistry}
+	 * is present.
+	 * </p>
+	 *
+	 * @param editPart
+	 *                     The edit part to test
+	 * @return
+	 * 		<code>true</code> if this edit part is part of a Papyrus environment (Using a Papyrus {@link ServicesRegistry}), <code>false</code> otherwise
+	 */
+	public static boolean isPapyrusPart(EditPart editPart) {
+		try {
+			return ServiceUtilsForEditPart.getInstance().getServiceRegistry(editPart) != null;
+		} catch (Exception ex) {
+			// Ignore & return
+			return false;
+		}
+	}
+
+	/**
+	 * <p>
+	 * Tests if the given View is a Papyrus View, by testing if a Papyrus {@link ServicesRegistry}
+	 * is present.
+	 * </p>
+	 *
+	 * @param view
+	 *                 The view to test
+	 * @return
+	 * 		<code>true</code> if this view is part of a Papyrus environment (Using a Papyrus {@link ServicesRegistry}), <code>false</code> otherwise
+	 */
+	public static boolean isPapyrusView(View view) {
+		try {
+			return ServiceUtilsForEObject.getInstance().getServiceRegistry(view) != null;
+		} catch (Exception ex) {
+			// Ignore & return
+			return false;
+		}
+	}
+
+	/**
+	 * <p>
+	 * Helper method to use the {@link ViewProviderService}.
+	 * </p>
+	 * <p>
+	 * This methods verifies that the edit part is a Papyrus Edit Part (Via {@link #isPapyrusPart(EditPart)}),
+	 * and then calls {@link ViewProviderService#isEnabled(IViewProvider, EditPart)}
+	 * </p>
+	 *
+	 * @param provider
+	 * @param editPart
+	 * @return
+	 *
+	 * @see ViewProviderService#isEnabled(IViewProvider, EditPart)
+	 */
+	public static boolean isEnabled(IViewProvider provider, View view) {
+		if (isPapyrusView(view)) {
+			try {
+				ViewProviderService service = ServiceUtilsForEObject.getInstance().getService(ViewProviderService.class, view);
+				return service.isEnabled(provider, view);
+			} catch (Exception ex) {
+				// Ignore & return
+				return false;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * <p>
+	 * Helper method to use the {@link EditPolicyProviderService}.
+	 * </p>
+	 * <p>
+	 * This methods verifies that the edit part is a Papyrus Edit Part (Via {@link #isPapyrusPart(EditPart)}),
+	 * and then calls {@link EditPolicyProviderService#isEnabled(IEditPolicyProvider, EditPart)}
+	 * </p>
+	 *
+	 * @param provider
+	 * @param editPart
+	 * @return
+	 *
+	 * @see {@link EditPolicyProviderService#isEnabled(IEditPolicyProvider, EditPart)}
+	 */
+	public static boolean isEnabled(IEditPolicyProvider provider, EditPart editPart) {
+		if (isPapyrusPart(editPart)) {
+			try {
+				EditPolicyProviderService service = ServiceUtilsForEditPart.getInstance().getService(EditPolicyProviderService.class, editPart);
+				return service.isEnabled(provider, editPart);
+			} catch (Exception ex) {
+				// Ignore & return
+				return false;
+			}
+		}
+
+		return false;
+	}
+
+}
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ViewProviderService.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ViewProviderService.java
new file mode 100644
index 00000000000..7a16c39b72b
--- /dev/null
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ViewProviderService.java
@@ -0,0 +1,78 @@
+/*****************************************************************************
+ * Copyright (c) 2018 EclipseSource and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   EclipseSource - Initial API and implementation (Bug 533701)
+ *
+ *****************************************************************************/
+package org.eclipse.papyrus.infra.gmfdiag.common.service;
+
+import org.eclipse.gmf.runtime.diagram.core.providers.IViewProvider;
+import org.eclipse.gmf.runtime.notation.View;
+import org.eclipse.papyrus.infra.core.services.IServiceFactory;
+import org.eclipse.papyrus.infra.core.services.ServiceException;
+import org.eclipse.papyrus.infra.core.services.ServicesRegistry;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.FrameworkUtil;
+import org.osgi.framework.ServiceReference;
+
+/**
+ * <p>
+ * A service used to increase the control diagrams have over the {@link IViewProvider}
+ * that should be enabled in that diagram. All generic Papyrus {@link IViewProvider} are expected to use this
+ * service before deciding if they should indeed be enabled.
+ * </p>
+ * <p>
+ * Note that this service is here to provide an additional pre-check to determine if a
+ * provider is allowed to work in a specific diagram. However, this service knows nothing
+ * about the internal requirements/dependencies of a specific provider, and should not
+ * <strong>replace</strong> the {@link IViewProvider#provides(org.eclipse.gmf.runtime.common.core.service.IOperation)}
+ * method (i.e. the actual provider is still expected to run its own checks, in addition
+ * to calling this service).
+ * </p>
+ *
+ * @since 3.100
+ */
+public interface ViewProviderService {
+	/**
+	 * Tests whether the given provider is allowed in the context of that view
+	 *
+	 * @param provider
+	 * @param view
+	 * @return
+	 */
+	boolean isEnabled(IViewProvider provider, View view);
+
+
+
+	public static class Factory implements IServiceFactory {
+
+		@Override
+		public void init(ServicesRegistry servicesRegistry) throws ServiceException {
+			// Nothing
+		}
+
+		@Override
+		public void startService() throws ServiceException {
+			// Nothing
+		}
+
+		@Override
+		public void disposeService() throws ServiceException {
+			// Nothing
+		}
+
+		@Override
+		public ViewProviderService createServiceInstance() throws ServiceException {
+			BundleContext bundleContext = FrameworkUtil.getBundle(Factory.class).getBundleContext();
+			ServiceReference<ViewProviderService> serviceReference = bundleContext.getServiceReference(ViewProviderService.class);
+			return bundleContext.getService(serviceReference);
+		}
+
+	}
+}
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ViewProviderTester.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ViewProviderTester.java
new file mode 100644
index 00000000000..f2928331534
--- /dev/null
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/service/ViewProviderTester.java
@@ -0,0 +1,39 @@
+/*****************************************************************************
+ * Copyright (c) 2018 EclipseSource and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   EclipseSource - Initial API and implementation (Bug 533701)
+ *
+ *****************************************************************************/
+
+package org.eclipse.papyrus.infra.gmfdiag.common.service;
+
+import org.eclipse.gmf.runtime.diagram.core.providers.IViewProvider;
+import org.eclipse.gmf.runtime.notation.View;
+
+/**
+ * <p>
+ * A contribution to the {@link ViewProviderService}
+ * </p>
+ *
+ * @since 3.100
+ */
+public interface ViewProviderTester {
+
+	/**
+	 * Tests whether the given provider is allowed in the context of that edit part
+	 *
+	 * @param provider
+	 * @param editPart
+	 * @return
+	 * 		<code>false</code> if this tester explicitly rejects this provider in the context of that edit part;
+	 *         <code>true</code> otherwise.
+	 */
+	boolean isEnabled(IViewProvider provider, View view);
+}
+